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<b>let </b><font color="Maroon" title="c1">x0</font>, <font color="Maroon" title="c2">x1</font>, <font color="Maroon" title="c3">x2</font> be   <a href="real_1.html#NM1" title="REAL_1:NM.1">Real</a>;<br/><b>let </b><font color="Maroon" title="c4">f1</font>, <font color="Maroon" title="c5">f2</font> be   <a href="funct_2.html#NM1" title="FUNCT_2:NM.1">Function</a> of  <a href="numbers.html#K1" title="NUMBERS:func.1">REAL</a> , <a href="numbers.html#K1" title="NUMBERS:func.1">REAL</a> ;<br/>









<span class="p1"><a href="diff_1.html#K13" title="DIFF_1:func.13">[!</a><span class="default"><span class="p2">(<span class="default"><font color="Maroon" title="c4">f1</font> <a href="partfun3.html#K3" title="PARTFUN3:func.3">+</a> <font color="Maroon" title="c5">f2</font></span>)</span>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K13" title="DIFF_1:func.13">!]</a></span> = 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c4">f1</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span> <a href="real_1.html#K7" title="REAL_1:func.7">+</a> <span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c5">f2</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span></span>)</span> <a href="real_1.html#K9" title="REAL_1:func.9">-</a> <span class="p2"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><span class="p3">(<span class="default"><font color="Maroon" title="c4">f1</font> <a href="partfun3.html#K3" title="PARTFUN3:func.3">+</a> <font color="Maroon" title="c5">f2</font></span>)</span>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span></span>)</span> <a href="real_1.html#K10" title="REAL_1:func.10">/</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">x0</font> <a href="real_1.html#K9" title="REAL_1:func.9">-</a> <font color="Maroon" title="c3">x2</font></span>)</span>
<b>by </b><i><a class="ref" href="diff_1.html#T32" title="DIFF_1:th.32">DIFF_1:32</a></i>
<br/>.= 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c4">f1</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span> <a href="real_1.html#K7" title="REAL_1:func.7">+</a> <span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c5">f2</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span></span>)</span> <a href="real_1.html#K9" title="REAL_1:func.9">-</a> <span class="p2">(<span class="default"><span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c4">f1</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span> <a href="real_1.html#K7" title="REAL_1:func.7">+</a> <span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c5">f2</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span></span>)</span></span>)</span> <a href="real_1.html#K10" title="REAL_1:func.10">/</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">x0</font> <a href="real_1.html#K9" title="REAL_1:func.9">-</a> <font color="Maroon" title="c3">x2</font></span>)</span>
<b>by </b><i><a class="ref" href="diff_1.html#T32" title="DIFF_1:th.32">DIFF_1:32</a></i>
<br/>.= 
<span class="p1">(<span class="default"><span class="p2">(<span class="default"><span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c4">f1</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span> <a href="real_1.html#K9" title="REAL_1:func.9">-</a> <span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c4">f1</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span></span>)</span> <a href="real_1.html#K7" title="REAL_1:func.7">+</a> <span class="p2">(<span class="default"><span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c5">f2</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span> <a href="real_1.html#K9" title="REAL_1:func.9">-</a> <span class="p3"><a href="diff_1.html#K12" title="DIFF_1:func.12">[!</a><span class="default"><font color="Maroon" title="c5">f2</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K12" title="DIFF_1:func.12">!]</a></span></span>)</span></span>)</span> <a href="real_1.html#K10" title="REAL_1:func.10">/</a> <span class="p1">(<span class="default"><font color="Maroon" title="c1">x0</font> <a href="real_1.html#K9" title="REAL_1:func.9">-</a> <font color="Maroon" title="c3">x2</font></span>)</span>

;<br/>
<b>hence </b><a NAME="E2:6"/>
<span class="p1"><a href="diff_1.html#K13" title="DIFF_1:func.13">[!</a><span class="default"><span class="p2">(<span class="default"><font color="Maroon" title="c4">f1</font> <a href="partfun3.html#K3" title="PARTFUN3:func.3">+</a> <font color="Maroon" title="c5">f2</font></span>)</span>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K13" title="DIFF_1:func.13">!]</a></span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <span class="p1"><a href="diff_1.html#K13" title="DIFF_1:func.13">[!</a><span class="default"><font color="Maroon" title="c4">f1</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K13" title="DIFF_1:func.13">!]</a></span> <a href="real_1.html#K7" title="REAL_1:func.7">+</a> <span class="p1"><a href="diff_1.html#K13" title="DIFF_1:func.13">[!</a><span class="default"><font color="Maroon" title="c5">f2</font>,<font color="Maroon" title="c1">x0</font>,<font color="Maroon" title="c2">x1</font>,<font color="Maroon" title="c3">x2</font></span><a href="diff_1.html#K13" title="DIFF_1:func.13">!]</a></span>
 <b>by </b><i><a class="ref" href="xcmplx_1.html#T63" title="XCMPLX_1:th.63">XCMPLX_1:63</a></i>;<br/>


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